Macmanmatty's studio build questions

My outer wall is 1/2 durock and My current inner wall is made up of 9/16" OSB then 7/16" plywood and then a layer of 5/8' drywall I Got the plywood and osb for near free (1$ a sheet). The inner and outer walls are 6-7" and total air gap is 13-14" apart and are kind of a staggered stud wall there is a flanking path through some of the joists between the two as both are screwed to the joists or something that eventually makes contact with the joists. The ceiling is 7/16" plywood and then 3/4" plywood hung on resilent channel RC-8 with track lighting. I know I should have decoupled the top plate of the inner wall from the joists but I didn't want use sway braces they are expensive and i'm not sure that they'd even work in our hurricane prone area and was not willing to lose 6-8" from the new joists for decoupled ceiling. I figured that this wall setup would have to give as least as good isolation as a staggered stud wall if not better . For the outlets and audio connectors the wire or audio cables runs into blue plastic boxes sticking out 1/2" and the osb is cut around that then the plywood is cut just big enough to fit an outlet or audio connector behind it (there is a little more gap with audio connectors though) then a plastic blue 1/2" outlet extender is screwed to the plywood and then the 5/8" drywall then a foam outlet pad then the outlet cover is put on and caulked. I did not surface mount my electrical boxes sadly :cry: .I was going to use putty pads but they are expensive and after reading ir772 EFFECT OF ELECTRICAL OUTLET BOXES ON SOUND INSULATION OF A DOUBLE LEAF WALL. I got the impression that they would not be worth the money? But now I am hearing otherwise I can remove the durrock from the outside and install them if need be. I have only one close neighbor who has over 70 goats So I do not care about getting out. only sound getting in which there is at most of 72db C would my current wall assembly block out the sound to where I won't hear it up when recording?